ERROR!

WebMacro encountered an error while executing a template: StreamTemplate:PMS/view/InvoiceList.wm:
org.webmacro.PropertyException: Attempt to invoke method public java.lang.String org.paneris.jal.model.DDField.getDropDown(java.lang.String,java.lang.String) throws java.lang.Exception on object org.paneris.jal.model.DDField raised an exception: java.lang.NullPointerException
java.lang.NullPointerException at PMS/view/InvoiceList.wm:27.5